Abstract

On-line text-compression algorithms are considered, where compression is done by substituting substrings of the text according to some fixed dictionary (code book). Due to the long running time of optimal compression algorithms, several on-line heuristics have been introduced in the literature. In this paper we continue the investigations of Katajainen and Raita [4]. We complete the worst-case analysis of the longest matching algorithm and of the differential greedy algorithm for several types of special dictionaries and derive matching lower and upper bounds for all variants of the problem in this context.

Keywords

On-line algorithm data compression worst-case analysis

This research was partially supported by the Spezialforschungsbereich F003 “Optimierung und Kontrolle”, Projektbereich Diskrete Optimierung, by the Christian Doppier Laboratorium für Diskrete Optimierung and by a grant from the Hungarian Academy of Sciences (OTKA, No. T 016349).